VINELink is the tool built exactly for this situation. It stands for Victim Information and Notification Everyday, and it is a free service available at vinelink.com that allows victims and concerned parties to register for automatic notifications when an offender's custody status changes, including when they are released, transferred, or escape. You can sign up to receive alerts by email, phone, or text. This is the most reliable way to make sure you are not the last person to know.
Beyond VINELink, contact the counselor or victim advocate at the facility where he is currently held and let them know about the PFA and your safety concerns. Many facilities have victim notification programs of their own and can flag your case so that staff are aware of the situation around his release.
The prosecutor or victim services coordinator on the original case that resulted in the PFA is another contact worth reaching out to. They can advise you on what additional legal protections may be available, including whether the PFA can be extended or modified to provide additional distance and notification requirements upon release.
Document what happened when he showed up at your job after his last release. That information is relevant if you ever need to reinforce the PFA in court.